JPS63137423A - X-ray mask-pattern-forming method - Google Patents

Abstract

PURPOSE:To obtain an X-ray mask having excellent quality highly accurately, by growing and forming a rigid thin film on the side wall of a resist pattern when the resist pattern for forming the pattern of an X-ray absorbing body is formed. CONSTITUTION:On an X-ray absorbing-pattern-supporting film 10, a conductor film 11 for plating, an Al thin film 12, a lower resist layer 13 and an upper resist film 14 are laminated. The upper resist layer 14 is exposed and developed, and a mask 14' is formed. RIE is performed with O2, and a resist mask 15 is formed. When the Al film 12 is etched, an AlxOy film 16 is grown. The AlxOy film protects the resist pattern. The deformation and position deviation of the pattern are prevented even if the X-ray absorbing pattern is formed. The AlxOy has high rigidity, can be attached to the resist excellently and is not separated in normal washing.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an X-ray mask pattern forming method, and in particular,
The present invention relates to a method for forming a fine pattern in an X-ray exposure mask.

(Prior art) In the production of X-ray exposure masks, etching methods, plating methods, lift-off methods, etc. are used to form X-ray absorbing patterns, but when forming fine patterns, there is no redeposition phenomenon, and the pattern quality is high. A plating method with good properties is considered to be promising.

Hereinafter, the conventional plating method will be explained using FIG. 2.

First, as shown in FIG. 2(a), a plating conductive film 2, a lower resist 3, and an upper resist 4 are sequentially formed on the X-ray absorbing pattern support film 1.

Next, as shown in FIG. 2(b), an upper resist pattern 4' is formed.

Next, as shown in FIG. 2(c), a highly vertical resist pattern 3' is formed by dry etching using the upper resist pattern 4'.

Next, as shown in FIG. 2(d), a method is adopted in which an X-ray absorber material 6 is formed by plating on the portion from which the resist has been removed. Here, the resist pattern needs to have an aspect ratio (approximately 3 to 5) with a submicron pattern width and a height of approximately 1 μm or more.

(Problems to be Solved by the Invention) However, during the plating process for forming the X-ray absorber, (1) collapse of the resist pattern with a high aspect ratio, (2) lifting of the resist in part of the pattern corner, ( 3) Deformation and misalignment of the X-ray absorber pattern occur due to deformation of the resist pattern, which poses a problem when forming fine patterns for the X-ray absorber.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned problems and provide a method for forming an X-ray mask pattern with high pakuning accuracy and high quality.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides an XvA mask pattern forming method including a step of forming a resist pattern layer on a mask substrate, and a portion excluding this resist pattern layer. The resist pattern is etched and a rigid layer is attached to the side surface of the resist pattern. When forming a resist pattern for forming an X-ray absorber pattern, AJ, ○ are placed on the side wall of the resist pattern.
, in which a thin film is grown and formed.

(Function) According to the present invention, when forming a resist pattern for forming an X-ray absorber pattern, a rigid layer (A1.O, thin film) is grown on the side wall of the resist pattern. A JX formed in
Oy *The film causes (1) collapse of the resist pattern;
(2) Resist lifting in some pattern corners, (3)
) It is possible to prevent deformation and positional shift of the X-ray absorber pattern due to deformation of the resist pattern, prevent deformation of the resist pattern during production of the X-ray absorber pattern, and strengthen adhesion to the base material.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a manufacturing process diagram showing the method for forming an XvA mask pattern of the present invention.

First, as shown in FIG. 1(a), the X-ray absorption pattern support Il! 10, a conductive film 11 for plating, an Al
1 film 12, a lower resist layer 13, and an upper resist layer 14 are formed. In this way, a mask substrate for XvA exposure is manufactured.

Next, as shown in FIG. 1(b), the upper resist 14 is exposed and developed using ultraviolet light, electron beam exposure, etc. to form a desired upper resist pattern 14'.

Next, as shown in FIG. 1C, using the upper resist pattern 14' as a mask, the lower resist 13 is dry etched by 0tRIB (oxygen reactive ion etching) to form a resist pattern 15.

Next, as shown in FIG. 1(d), the lower resist 1
After the 01 RIE in step 3, the Ae thin film 12 is dry etched by successively performing O and RIB. An example of dry etching conditions for this AI thin film 12 is 02 flow rate of 10°. , the pressure is 2 Pa and 200 W, and the thickness of the AJ thin film 12 before processing is approximately 100 to 200. When the AI thin film 12 is dry etched by RIE, an A Il++ Oy* film 16 is formed on the peripheral side walls of the resist pattern that has already been formed due to the reaction between O2 and Af.
is grown and formed.

This AlN0V thin film 16 protects the resist pattern,
Even when forming an X-ray absorber pattern, deformation and positional shift of the resist pattern can be prevented.

Above, we have explained an example in which the A1 layer is formed directly under the resist, but in addition to this, sputtering can be performed using a thin film that forms a rigid oxide such as Ti, Sn, Ta, Ti4, etc. to reattach it to the resist layer. In this case, since it is necessary to grow the mask pattern in a portion that does not have a resist layer, it is necessary to completely remove the portion other than the area under the resist pattern.

Also, A1. tOs is the most preferable material because it has high rigidity, easily adheres to the resist pattern, and cannot be easily removed from the resist pattern by normal cleaning.

Although not shown, the portion from which the resist has been removed is plated using a conventional method to form an X'-ray absorber pattern.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, according to the present invention, a rigid layer (An, O, thin film) is attached to the side wall of the resist pattern during mask pattern formation. This layer eliminates deformation and positional shift of the X-ray absorber bag due to collapse of the resist pattern, lifting of part of the resist pattern at pattern corners, deformation of the resist pattern, etc., and prevents deformation of the resist pattern during the production of the X-ray absorber pattern. It can be prevented.

Further, the adhesion to the underlying material can be strengthened.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the manufacturing process showing the X-ray mask pattern forming method of the present invention, and FIG. 2 is a sectional view of the process of a conventional plating method. DESCRIPTION OF SYMBOLS 10... X-ray absorption pattern support film, 11... Conductive film for plating, 12... A1 thin film, 13... Lower layer resist, 14... Upper layer resist, 14'... Upper layer resist pattern, 15...Resist pattern, 16...
AI, lOa Fill.

Claims (1)

[Claims] (a) A step of forming a resist pattern layer on a mask substrate; (b) A step of attaching a rigid layer to the side surface of the resist pattern while etching a portion excluding the resist pattern layer. An X-ray mask pattern forming method comprising: